STLalgorithm算法includes(23)
includes原型:
std::includes
template <class InputIterator1, class InputIterator2>
bool includes ( InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2 );
template <class InputIterator1, class InputIterator2, class Compare>
bool includes ( InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2, Compare comp );
该函数是测试 [first1,last1)里面是否包含了``[first2,last2)里面的所有元素。
也就是说,后面那一个区间是否是前一个区间的子集。
[first1,last1)和[first2,last2)里面的元素应该先排好序,并且是使用同一规则排序。
其行为类似如下:
1 | 2 |
1 | template <class InputIterator1, class InputIterator2> |
一个简单的例子:
#include
#include
#include
#include
using namespace std;
void includes2(){
vector
array<int,3> ai{19,100,56};
vector
sort(vi.begin(),vi.end());
sort(ai.begin(),ai.end());
sort(v2.begin(),v2.end());
cout<<"at first,vi=";
for\_each(vi.begin(),vi.end(),\[\](int i){cout<<i<<" ";});
cout<<endl;
cout<<"at first,ai=";
for\_each(ai.begin(),ai.end(),\[\](int i){cout<<i<<" ";});
cout<<endl;
cout<<"at first,v2=";
for\_each(v2.begin(),v2.end(),\[\](int i){cout<<i<<" ";});
cout<<endl;
if(includes(vi.begin(),vi.end(),ai.begin(),ai.end()))
cout<<"includes(vi.begin(),vi.end(),ai.begin(),ai.end()) return true!"<<endl;
else
cout<<"includes(vi.begin(),vi.end(),ai.begin(),ai.end()) return false!"<<endl;
if(includes(vi.begin(),vi.end(),v2.begin(),v2.end()))
cout<<"includes(vi.begin(),vi.end(),v2.begin(),v2.end()) return true!"<<endl;
else
cout<<"includes(vi.begin(),vi.end(),v2.begin(),v2.end()) return false!"<<endl;
}
运行截图:
如果不排序,则有会发生错误!
例如下面的例子:
#include
#include
#include
#include
using namespace std;
void includes2(){
vector
array<int,4> ai{19,100,56,1};
vector
// sort(vi.begin(),vi.end());
// sort(ai.begin(),ai.end());
// sort(v2.begin(),v2.end());
cout<<"at first,vi=";
for\_each(vi.begin(),vi.end(),\[\](int i){cout<<i<<" ";});
cout<<endl;
cout<<"at first,ai=";
for\_each(ai.begin(),ai.end(),\[\](int i){cout<<i<<" ";});
cout<<endl;
cout<<"at first,v2=";
for\_each(v2.begin(),v2.end(),\[\](int i){cout<<i<<" ";});
cout<<endl;
if(includes(vi.begin(),vi.end(),ai.begin(),ai.end()))
cout<<"includes(vi.begin(),vi.end(),ai.begin(),ai.end()) return true!"<<endl;
else
cout<<"includes(vi.begin(),vi.end(),ai.begin(),ai.end()) return false!"<<endl;
if(includes(vi.begin(),vi.end(),v2.begin(),v2.end()))
cout<<"includes(vi.begin(),vi.end(),v2.begin(),v2.end()) return true!"<<endl;
else
cout<<"includes(vi.begin(),vi.end(),v2.begin(),v2.end()) return false!"<<endl;
}
运行截图:
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//写的错误或者不好的地方请多多指导,可以在下面留言或者点击左上方邮件地址给我发邮件,指出我的错误以及不足,以便我修改,更好的分享给大家,谢谢。
转载请注明出处:http://blog.csdn.net/qq844352155
author:天下无双
Email:coderguang@gmail.com
2014-9-16
于GDUT
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